This disclosure relates to a display device. Transparent displays have been proposed that display an image while allowing the background behind the display to be seen. Transparent displays can be used in an automotive window or a store window, for example. Transparent displays can utilize self-light-emitting elements, such as organic light-emitting diode (OLED) elements. An OLED element is a current-driven self-light-emitting element and therefore, eliminates the necessity of backlight. In addition to this, the OLED display element has advantages to achieve low power consumption, wide viewing angle, and high contrast ratio.